Growing use of nanotechnology stirs hopes, fears / The future is now: Nanotechnology is already in hundreds of everyday products, but questions remain about long-term environmental effects

Ralph Hermansson, Chronicle Staff Writer

Published
4:00 am PDT, Monday, July 9, 2007

Bacteria-proof forks and knives. Pants that never get stains. Computer chips with a considerably better memory, making conventional chips seem almost senile. Sports equipment made of materials that are much harder yet more lightweight than today.

Science fiction? Not at all, these products are readily available -- thanks to nanotechnology.

The somewhat outdated mantra "less is more" has probably never been more accurate than when it comes to nanotechnology. In this science, it's all about tiny details (nanos is the Greek word for dwarf). One nanoscale is a billionth of a meter, about 50,000 times smaller than the width of a human hair.

At that extremely small scale, very unusual properties of matter emerge. If you bring aluminum down to 20 nanometers, the surface-area-to-volume ratio changes so dramatically that explosions occur. This is why aluminum is used in rocket fuel to give some additional boost.

When manipulating atoms and molecules at this small level, engineers can build products that are many times stronger than conventional materials and yet lightweight.

New bicycles that are much more robust and still much lighter than most bikes today are but one example. Tennis rackets, skis and golf clubs are other items for which nanotechnology offers great advantages over graphite in strength, durability and weight.

The new technology is also being used to make longer-lasting batteries. Today, there are more than 500 products on the market that use nanotechnology in one way or another.

But critics point out that there are risks inherent in nanotechnology.

One popular use of nanotechnology is adding an ultrathin silver coating on kitchenware such as knives and forks so that bacteria can't stick to the surface. But not all bacteria are bad. Some are beneficial and actually crucial to building the body's immune system. If the environment becomes too clean and too antiseptic, experts say, there can be health hazards.

"There are a couple of concerns," said Andrew Maynard, science adviser at the Project on Emerging Nanotechnologies, a government-funded policy research institute in Washington, D.C.

"There is a risk if bacteria develop a resistance to antibacterial materials. If and when this product gets out to the environment, there is also a potential risk."

Silver nano particles are of special concern. These germ-killing particles are used in shoe liners, food-storage containers and washing machines, among other things. Since there is a risk that the particles escape into the aquatic environment, beneficial bacteria and other organisms may be killed. For this reason, the U.S. Environmental Protection Agency is demanding evidence that these kinds of products are not harmful to the environment.

Other areas of concern are transparent sunscreens that block all ultraviolet rays just as efficiently as any zinc paste. When you apply this type of sunscreen to avoid skin cancer, small nanoscale particles can enter your system through the skin. The effects this might have in the long run are hard to predict.

"There are so many different nano particles that it's misleading to put them under one name," she said.

"All they have in common is the size. It's kind of like comparing butter, basketballs and a boulder -- you just can't. Some particles probably will have issues and some won't be dangerous."

Even if there are risks, Maynard is convinced that nanotechnology, or rather different nanotechnologies, can be revolutionary.

He points to three different areas of special interest. One is that nanotechnology can help build new, high-performance materials already used in sports equipment but which can also be used to build cars or airplanes in the future.

The medical market is also of special interest. With the help of nanotechnology, the hope is to design new, more efficient drugs with fewer or no side effects. Nanotechnology could enhance the precision of drugs that have one highly specialized mission, like finding and killing cancer cells or tumors.

"The research results so far have been totally promising," Peterson said. "The animal testings have been very hopeful, and I think that in five to 10 years there will be new, very efficient drugs to fight cancer on the market."

Computer science is another area where nanotech is said to have a great future. In May, IBM introduced the next generation of powerful computer chips using the technology. Not only will the chips have a 35 percent higher performance, thanks to microscopic vacuum channels, it won't overheat.

"All in all, I think nanotechnologies will mean a profound change in how we are doing things," Maynard said.

Nanotechnolgy is not really a new science. The term was coined back in 1986, and experts have been predicting major breakthroughs ever since.

"Some innovations are coming about slower than people anticipated," Maynard said.

However, in five or 10 years, Maynard thinks we may look back and see the seeds of great change:

"Thanks to nanotechnology, we can today engineer electronic things on a much smaller scale. In the future, I think that some of the rather trivial products you see out on the market now may very well represent the first step for new materials that will be used in much more sophisticated ways."